Drop countermeasures for electronic device

ABSTRACT

An electronic device comprises a housing, a motion sensor configured to sense motion of the housing, and a processor configured to determine an impact geometry based on the motion. A countermeasure system comprises an actuator coupled to an actuated member. The actuated member is operable by the actuator to modify the impact geometry, so that impact energy is redirected away from an impact sensitive component of the electronic device to an energy absorbing component of the electronic device.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application is a divisional patent application of U.S. patentapplication Ser. No. 13/794,393, filed Mar. 11, 2013 and titled “DropCountermeasures for Electronic Device,” the disclosure of which ishereby incorporated herein by reference in its entirety.

TECHNICAL FIELD

This subject matter of this disclosure relates generally to electronicdevices, and specifically to active protection systems for devicessubject to potential hazards including dropping, shock, and impact. Inparticular, the disclosure relates to active countermeasure and damagemitigation systems suitable for a range of different electronic devices,including, but not limited to, mobile and cellular phones, smartphones,tablet computers, personal computers, personal digital assistants, mediaplayers, and other electronic devices.

BACKGROUND

In use, modern electronic devices are subject to a wide range ofdifferent environmental effects, including temperature extremes,humidity, physical contamination, and potential loss or damage due tophysical hazards including dropping, shock, compression and impact.These considerations can be particularly relevant to portable electronicand mobile device applications, where sensitive control and displaycomponents may be exposed to the external environment, increasing therisk of damage due to accident or misuse.

A number of alternatives have been advanced to address these concerns,but there remains a need for improved techniques suitable for advancedconsumer electronics and other digital device applications, without allthe limitations of the prior art. In particular, there is a need foractive drop damage mitigation and impact countermeasure systems,suitable for modern electronic devices designed for an ever-wider rangeof operating environments, and exposed to a correspondingly wider rangeof environmental risk factors, including dropping, shock, compression,impact, and other potentially adverse operational effects.

SUMMARY

This disclosure relates to drop damage mitigation and impactcountermeasures for electronic devices. In various examples andembodiments, the electronic device includes a housing, a motion sensorconfigured to sense motion of the housing, and a processor configured todetermine an impact geometry based on the motion.

The countermeasure system may include an actuator coupled to an actuatedmember, where the actuated member is operable by the actuator to modifythe impact geometry. As a result, impact energy can be redirected froman impact sensitive component of the electronic device to an energyabsorbing component of the electronic device.

Depending on application, a proximity detector may be configured tosense proximity of a potential impact surface external to the device,and the processor may be configured to determine the impact geometrybased on the proximity of the external surface. For example, theproximity detector may include a camera, and the processor may beconfigured to determine the proximity of the external surface based onimage data from the camera. The motion sensor may also include anaccelerometer, and the processor may be configured to determine theimpact geometry based on acceleration of the housing, with respect tothe external surface.

In some examples, the actuated member may include a mass operable toadjust the impact geometry by changing an attitude of the housing, withrespect to the external surface. The mass may be coupled to an unstablerotational axis, and the processor may be configured to adjust theattitude of the housing by repeated operation of the actuator indifferent directions, imparting angular momentum to the device indifferent directions about the unstable axis during tumbling motion.

The actuated member may also be operable to change the impact geometryby extending in a proud relationship from the housing of the electronicdevice, so that the impact energy is redirected from the housing to theactuated member. For example, the actuated member may include a logoconfigured to identify the electronic device, or a control memberconfigured to control operation of the electronic device, and operableby the actuator to extend in a proud relationship from a cover glass sothat the impact energy is redirected from the cover glass to the logo orcontrol member.

The actuated member can also include the cover glass, operable by theactuator to depress into a recessed relationship with respect to thehousing of the electronic device, so that the impact energy isredirected from the cover glass to the housing. Alternatively, theactuated member may include a connector coupling operable to retain orrelease a connector, based on the motion of the housing, or a coverpanel operable to cover the cover glass so that the impact energy isredirected from the cover glass to the cover panel.

Exemplary methods of operation include sensing motion of a housing foran electronic device, determining an impact geometry based on themotion, and operating an actuator to modify the impact geometry. Forexample, an actuated member may be actuated to redirect impact energyfrom an impact sensitive component of the electronic device to an energyabsorbing component of the electronic device.

Depending on application, operation may also include sensing proximityof a potential impact surface external to the housing of the electronicdevice, where the impact geometry is determined based on the proximityof the external surface. For example, sensing proximity of the externalsurface may include processing image data from a camera, in order todetermine proximity.

Where the actuated member comprises a mass coupled to an unstablerotational axis of the device, modifying the impact geometry may includecoupling the actuated member or mass to the unstable rotational axis, inorder to change an attitude of the housing with respect to the externalsurface. For example, changing the attitude of the housing may includerepeated actuation of the mass to impart angular momentum in differentdirections about the unstable axis, during tumbling motion of theelectronic device.

Operating the actuator may also include extending the actuated member ina proud relationship from the housing of the electronic device, in orderto redirect the impact energy from the housing to the actuated member.For example, the actuated member may be extended in a proud relationshipfrom a cover glass of the electronic device, in order to redirect theimpact energy from the cover glass to the actuated member.Alternatively, the cover glass may be depressed into a recessedrelationship with respect to the housing of the electronic device, inorder to redirect the impact energy from the cover glass to the housing.

In additional examples, operating the actuator may include retaining orreleasing an external connector, based on the motion of the housing.Alternatively, a cover panel may be deployed over the cover glass of theelectronic device, in order to redirect the impact energy from the coverglass to the cover panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a front perspective view of a digital electronic device withactive drop damage mitigation and impact countermeasures.

FIG. 1B is a rear perspective view of the device.

FIG. 2 is a block diagram illustrating internal and external features ofthe device.

FIG. 3A is a perspective view illustrating a momentum-coupled dropdamage mitigation or countermeasure system for the device, with aproximity sensor.

FIG. 3B is a schematic view illustrating a second example of thecountermeasure system, with a rotary angular momentum-coupled actuator.

FIG. 4A is a schematic illustration of a drop damage mitigation systemfor the device, with an actuated control device.

FIG. 4B is a schematic illustration showing a second example of the dropdamage mitigation system, with an actuated logo member.

FIG. 4C is a schematic illustration showing a third example of the dropdamage mitigation system, with an actuated impact absorbing member.

FIG. 4D is a schematic illustration showing a fourth example of the dropdamage mitigation system, with an actuated cover glass.

FIG. 5A is a schematic illustration of a mechanically coupled dropdamage countermeasure system for the device, with an audio jack orconnector coupling.

FIG. 5B is a schematic illustration showing a second example of themechanically coupled countermeasure system, with an audio jack orconnector decoupling.

FIG. 6 is a front perspective view illustrating a mechanically coupleddrop damage mitigation system for the device, with an actuated cover.

FIG. 7 is an alternate perspective view of the device, with a differentcover configuration.

FIG. 8 is a perspective view of the device, with the cover in an ejectedposition.

DETAILED DESCRIPTION

FIG. 1A is a perspective view of digital electronic device 10, in acommunications embodiment. FIG. 1B is a rear perspective view of device10, as shown in FIG. 1A. In these particular configurations, device 10includes front cover glass 12 with display window 14 defined betweenborders 15, and housing assembly 16 is configured for use as a mobilephone or smartphone application. Alternatively, device 10 may beconfigured as a media player, digital assistant, tablet computer,personal computer, computer display, or other electronic device, ineither portable or stationary form.

Cover glass 12 is typically formed of a glass or transparent ceramicmaterial, for example silica glass or an aluminum oxide or sapphirematerial, or a clear plastic polymer such as acrylic or polycarbonate.Housing 16 and frame 18 may be formed of metals such as aluminum andsteel, or from plastic, glass, ceramic, or composite materials, andcombinations thereof.

As shown in FIGS. 1A and 1B, front cover glass 12 may be coupled to top,bottom, and middle sections 16A, 16B, and 160 of housing assembly 16,for example utilizing a bezel or frame assembly 18. Middle housingsection 160 extends across the back surface of device 10, forming backplate (or middle plate) 16D, between back cover glass insets 12B, asshown in FIG. 1B.

Additional cover glass components such as lens cover 120 may also beprovided. Alternatively, a single back cover glass section 12 (or 12B)may be used. Middle plate 16D may also be extended to coversubstantially the entire back surface of device 10, providing asubstantially unitary configuration for the back cover of housing 16.

Display window 14 is typically configured for a touch screen or otherdisplay component, as defined between border region(s) 15 of cover glass12. Depending on configuration, cover glass 12 and housing 16 may alsoaccommodate additional control and accessory features, including, butnot limited to, home, menu and hold buttons, volume controls, and othercontrol devices 20, audio (e.g., speaker or microphone) features 22,sensor and camera features 24, lighting and indicator (e.g., lightemitting diode or flash) features 26, mechanical fasteners 28, connectorports 30, and access ports 32, e.g., for a subscriber identity module orSIM card, a flash memory device, or other internal component ofelectronic device 10.

As shown in FIG. 1B, device 10 also includes countermeasure system 40,as configured to mitigate damage from dropping, impact, and otheraccident or misuse. In this particular configuration, for example,countermeasure system 40 includes a gyro, accelerometer, magneticsensor, or other motion sensor (g) 42 for sensing motion of housing 16,and processor (μp) 44 for determining or predicting impact geometry,based on the motion. Countermeasure system 40 may also include one ormore cameras or other proximity sensors 24.

In operation of system 40, actuator or actuated mass (a/m) 45 isoperable to reduce or mitigate impact damage to device 10, or thepotential therefor. In particular, actuator 45 may be operated to changethe impact geometry by repositioning the actuated mass to alter theattitude of housing, 16, or by reconfiguring or actuating a component ofhousing 16. As a result, impact forces and impact energy may beredirected from sensitive components of device 10 to energy absorbingcomponents, as described below.

FIG. 2 is a block diagram illustrating various internal and externalcomponents of electronic device 10, including drop damage mitigation andimpact countermeasure system 40. In this particular example, system 40includes an accelerometer or other motion sensor 42, display 43,processor or controller 44, and actuator 45.

In addition, electronic device 10 and system 40 may also include variouscontrol mechanisms 20 and audio devices 22, cameras and other proximitysensors 24, and additional lighting, indicator, connector, and accessfeatures 26, 30, and 32, as variously disposed and provided within coverglass 12 and housing 16. Device 10 thus encompasses a range of differentelectronics applications, as described above with respect to FIGS. 1Aand 1B, as well as additional hybrid devices including smartphones withmedia player capabilities, game players, remote global positioning andtelecommunications devices, and laptop, desktop, notebook, handheld andultraportable computer devices and displays.

Processor/controller 44 includes microprocessor (μp) and memorycomponents configured to execute a combination of operating system andapplication firmware and software, in order to control device 10 withcountermeasure system 40, and to provide various additionalfunctionality including, but not limited to, voice communications, voicecontrol, media playback and development, internet browsing, email,messaging, gaming, security, transactions, navigation, and personalassistant functions. As shown in FIG. 2, processor/controller 44 iselectronically coupled in signal and data communication with motionsensor 42, display 43, actuator 45, control and audio devices 20 and 22,and cameras and proximity sensors 24. Processor/controller 44 may alsoinclude communications interface and other input-output (IO) devicesconfigured to support connections 30 and 46, with various hard-wired,wireless, audio, visual, infrared (IR), and radio frequency (RF)connections to one or more external accessories 47, host devices 48 andnetworks 49.

When electronic device 10 is subject to dropping, impact, or otherpotential hazard, motion and proximity data are acquired from one ormore sensor systems including, but not limited to, cameras and otherproximity sensors 24, and accelerometers, gyros, and other motionsensors 42. The data are analyzed by processor components such asprocessor/controller 44, in order to apply suitable countermeasures tolessen the potential for damage to device 10, for example via operationof actuator 45. Alternatively, system 40 may also deploy or operate oneor more auxiliary devices 20, 22, 24, and 26, or connector ports 30,either independently or in combination with actuator 45.

Suitable countermeasures can include moving one or more devices 20, 22,24 or 26, to a more favorable impact position, for example throughshifting or rotating elements of the various control, audio, camera,lighting, and sensor systems. Alternatively, actuator 45 may be employedto shift or rotate a particular mass, in order to change the orientationof device 10 via momentum coupling to housing 16. Additional optionsinclude protective countermeasures to change the impact severity, forexample by actuating or pulling cover glass 12 sub flush or below theperimeter of housing 16, closing a cover system, deploying an airbagsystem or other energy absorbing device, or changing the shape ormaterial properties of one or both of cover glass 12 and housing 16, inorder to provide shock and energy absorbing properties, based thevarious embodiments and examples described below.

FIG. 3A is a perspective view illustrating a momentum-coupled dropdamage mitigation or countermeasure system 40 for device 10, withproximity sensor 24. As shown in FIG. 3A, device 10 may experience adropped or falling condition in direction D, with arbitrarythree-dimensional rotational attitude A. The direction of motion (D) andattitude (A) may be determined with respect to local gravitational fieldvector g or potential impact surface S, or based on another arbitraryreference system.

In this particular example, countermeasure system 40 includes a gyro,accelerometer, or other motion sensor (g) 42, processor (μp) 44,actuator/actuated mass 45, and proximity sensor 24. Processor 44determines attitude A, and motion D, including velocity and angularrotation data, based on signals from one or both of proximity sensor 24and motion sensor 42.

For example, motion sensor 42 may provide angular rotation andacceleration data with respect to local gravitational field g, andproximity sensor 24 may provide position, velocity, and attitudeinformation with respect to potential impact surface S, or otherexternal reference. Suitable technologies for proximity sensor 24include general-purpose cameras and other dedicated-use proximitydetectors 24, for example and infrared, optical, and ultrasonic systems.

Alternatively, one or more audio components 22 may be utilized forproximity detection, for example by emitting a chirp or ultrasonicpulse, and determining height, speed, and orientation based on thereflected signal or “bounce” from nearby surfaces. Potential ultrasonicor audio sensing techniques could utilized data not only from the groundor other impact surface, but also signals from walls, ceilings,furniture, and even the user or other nearby objects.

In camera-based embodiments of proximity sensor 24, processor 44 mayutilize motion capture software or firmware in order to convert imagedata from sensor 24 to velocity, attitude, and positional data.Alternatively, other software and firmware systems may be utilized todetermine motion D, attitude A, and the proximity of external surface S,based on data from one or both of proximity sensor 24 and motion sensor42.

In operation of countermeasure system 40, processor 44 determines apotential hazard damaging event for device 10 based on data from one orboth sensors 24 and 42, for example by predicting an impact geometry forhousing 16 on surface 5, based on motion data from motion sensor 42 andproximity data from proximity sensor 24. In addition, processor 44 mayalso predict attitude A of housing 16 on impact, based on rotationalvelocity and other data from one or both sensors 24 and 42.

Based on the impact geometry, as determined by processor 44, actuator 45is operable to provide a particular momentum coupling or modification tohousing 16, for example by linear actuation of a mass m, in order tochange the rotational velocity and angular momentum of housing 16 priorto impact. For example, processor 44 may operate actuator 45 to changeattitude A of housing 16 with respect to surface S, in order to redirectimpact energy from cover glass 12 (e.g., at a corner or otherimpact-sensitive area), to a less sensitive surface or component ofhousing 16, such as the back of device 10, or another energy absorbingsurface.

FIG. 3B is a perspective view illustrating a second example ofcountermeasure system 40, with a rotary angular momentum coupledactuator (a/R) 45. In this example, actuator 45 spins up (or down) adisk or other rotational component R, in order to change the angularmomentum of housing 16, as a fraction of the total angular momentum ofdevice 10.

Depending on embodiment, actuator 45 may operate a dedicated (linearlyactuated) mass m or (rotationally actuated) component R, or anothercomponent of device 10, for example a camera lens, speaker element,vibration motor, disk drive, or other component of a control device orcontrol mechanism 20, audio device 22, camera or sensor 24, orlighting/indicator feature 26. As a result, attitude A is modified atthe predicted point of impact with surface S, or other external surfaceor object, and impact energy can redirected from one component toanother, based on the modified attitude A of housing 16 at impact.

In general, the actuated mass may be relatively small, as compared tothe mass of device 10 and housing 16. Nonetheless, even relatively smallangular and linear momentum couplings may have a substantial effect onattitude A at impact. This is particularly true for tumbling motionscharacteristic of a drop or falling event, because the intermediate axisof rotation (that is, the middle moment of I_(x), I_(y), and I_(z)) isinherently unstable. Thus, even relatively small changes in thecorresponding angular momentum (L_(x), L_(y), L_(z)) may have asubstantial effect on attitude A, at the predicted time of impact.

Where tumbling motion occurs about an unstable axis, moreover, angularmomentum is typically transferred from one axis x, y, z, to another.Thus, actuation of a linear mass m or rotational body R may ultimatelyresult in substantially different angular momentum components L_(x),L_(y), L_(z), depending upon timing, particularly when the mass m orrotational body R is coupled with the unstable (intermediate) inertialaxis or moment I_(x), I_(y), I_(z). As a result, relatively largeeffects in ultimate attitude A (e.g., at impact) can be achieved, forexample by repeated or pulsed operation of actuator 45, either in thesame or different directions, depending upon attitude A and motion D, asdetermined by controller/processor 44.

FIG. 4A is a schematic illustration showing drop damage mitigationsystem 40 for electronic device 10, with an actuated control mechanism(or member) 20. In this example, mitigation system 40 includes a cameraor other proximal sensor 24, with actuator 45 coupled to control member20, for example a menu button, home button, or other control mechanismconfigured to control operation of device 10, as disposed in front (orback) glass 12.

In operation of the exemplary system in FIG. 4A, proximal sensor 24 isutilized to detect an imminent impact, for example a front or back dropevent onto a hard surface. System 40 controls actuator 45 based on thepredicted impact, as determined by processing data from sensor 24, withor without additional data from a gyro or other motion sensor 42.Actuator 45 is configured to actuate control device 20, for example bypositioning the home button or other control surface into a proudrelationship with respect to cover glass 12.

As a result, impact energy is redirected from cover glass 12 (or othersensitive components of device 10) to control device or control member20, which is configured to absorb the impact energy will less likelihoodof damage. For example, control device 20 may include a spring-biascontrol button or other control surface, which prevents face-on impactonto cover glass 12, reducing the risk of damage to cover glass 12. Inthis configuration, countermeasure system 40 also reduces the likelihoodof an air burst or other potentially damaging event for sensitive audiocomponents 22, for example a microphone or speaker cone.

FIG. 4B is a schematic illustration showing a second example of dropdamage mitigation system 40, with an actuated logo structure or member50. In this example, mitigation system 40 includes proximity sensor 24,with actuator 45 coupled to logo member 50 or other actuated member inthe back glass or back cover of device 10.

In operation of the exemplary system in FIG. 4B, system 40 determines animpact based on data from one or both of a camera or proximal sensor 24and motion sensor 42, for example a back drop event. Based on thepredicted impact or other potential hazard, processor 44 directsactuator 45 to position logo member 50 in a proud or extended positionwith respect to cover glass 12 (or other back surface) of device 10,redirecting impact energy to a spring bias element or otherenergy-absorbing structure in logo member 50, as described above foractuated control member 20 as shown in FIG. 4A.

FIG. 4C is a schematic illustration showing a third example of dropdamage mitigation system 40, with an actuated impact absorbing member52. In this example, mitigation system 40 includes a “stilt” or other(e.g., spring-biased) member 52, which is configured to project fromhousing 16 when operated by actuator 45.

In operation of the exemplary system in FIG. 40, processor 44 directsactuator 45 to operate a “stilt” or other projection member 52 inresponse to a dropping condition or predicted impact, as determinedbased on data from one or both of proximal sensor 24 and motion sensor42. Projection member 52 is configured to absorb impact energy, reducingthe risk of damage by redirecting the impact energy away from sensitivecomponents of device 10, including, but not limited to, cover glasscomponent(s) 12.

Depending upon embodiment, two or more actuated projections or otherimpact energy absorbing members 52 may be provided, for example one fromeach side of housing 16. Projection members 52 may also be combined withother designs for mitigation system 40, for example the actuated controland logo members of FIGS. 4A and 4B, above, or any of the other designsherein. In these combined configurations, different actuated membersincluding, but not limited to, components 20, 22, 24, 26, 30, 50, and52, may be simultaneously deployed, or individually actuated based on apredicted impact on a particular front, back, or side surface of device10, as determined by damage mitigation system 40 based on data from oneor more proximity and motion sensors 24 and 42.

FIG. 4D is a schematic illustration showing a fourth example of dropdamage mitigation system 40, with cover glass protection. In thisexample, one or more actuators 45 are coupled to cover glass 12, housing16, or both. Upon determination of a drop condition, impact, or otherhazard, damage mitigation system 40 directs actuator to position housing16 in a proud relationship with respect to cover glass 12, as shown inFIG. 4D, so that impact energy is redirected from cover glass 12 toenergy absorbing structures in housing 16.

For example, actuator 45 may be coupled to a piezoelectric or otherelectro-active material, in order to pull or recess cover glass 12 belowthe level of housing 16 (see arrow CG). Alternatively, actuator 45 maybe coupled to an electro-active polymer or other electro-active materialin housing 16, in order to position housing 16 above (proud of) coverglass 12 (see arrow H). In additional examples, actuator 45 provides acombination of both functions, with either individual or joint actuationof housing 16 and cover glass 12, in order to position housing 16 forredirecting impact energy away from cover glass 12, and other sensitivecomponents of device 10.

FIG. 5A is a schematic illustration of a mechanically coupled dropdamage countermeasure system for device 10, with audio jack or connectorcoupling actuator 45. In this example, countermeasure system 40 includesactuator 45 coupled to a headphone jack or other external connector 54,as configured for coupling to device 10 via connector one or moreapertures or ports 30.

In operation of the exemplary system in FIG. 5A, a drop event or otherpotential hazard is determined by countermeasure system 40, for examplewith substantially free fall or tumbling motion in direction D. Inresponse, actuator 45 may be directed to retain connector 54 withinconnector port 30, for example via a spring bias or electromagneticactuator system configured to generate a coupling tension or retentionforce along arrow C, sufficient to overcome the combined weight andacceleration forces on housing 16 and device 10. As a result, device 10may be suspended from cable 56, avoiding impact and redirecting thepotential impact energy to a combination of connector port 30, connector54, and cable 56.

FIG. 5B is a schematic illustration showing a second example ofmechanically coupled countermeasure system 40, as shown in FIG. 5A, withaudio jack or connector decoupling. In this example, countermeasuresystem 40 may indicates little or substantially no motion D, for examplewith device 10 positioned on (e.g., substantially horizontal) surface S.

In operation of the exemplary system in FIG. 5B, actuator 45 may beconfigured to release connector 54 from port 30, for example in responseto a decoupling force in the direction of arrow DC. Decoupling device 10from connector 54 and cable 56, in turn, reduces the risk of damage bypreventing device 10 from being pulled off surface S.

FIG. 6 is a front perspective view of electronic device 10 in analternate embodiment, for example a media player, tablet computer, padcomputer, or other computing device, or a computer monitor or display.In this particular configuration, device 10 is provided with amechanically coupled drop damage mitigation system 40 utilizing actuatedcover system 60, for example with one or more individual cover panels62.

Cover system 60 is coupled to device housing 16, for example using amagnetic or mechanical coupling, and configured to protect cover glass12 and other components of electronic device 10. Housing 16 may have asubstantially single-piece configuration, for example with a unitaryhousing and frame assembly, formed together with the back cover ofdevice 10.

Depending on application, the various components of countermeasuresystem 40 may be provided within device housing 16, cover system 60, ora combination thereof. For example, various sensor and processorcomponents 24, 42, and 44 may be provided within housing 16 ofelectronic device 10, as described above, with various energy-absorbingelements 64 and memory metal or spring-operated cover actuatorcomponents 65.

Cover actuators 65 may be located between cover panels 62 of coversystem 60, and/or between one or more cover panel(s) 62 and housing 16,as shown in FIG. 6. Alternatively, bimetallic strip or magneticallyactuated mechanisms 65 may be provided, utilizing an electric current orvoltage signal to generate or reverse a biasing force between adjacentcover panels 62, or between a cover panel 62 and device housing 16, inorder to open or close one or more cover panels 62.

In operation of system 40, a drop or other potentially damaging eventmay be indicated by substantially free fall or tumbling motion D, witharbitrary rotational attitude A. In response, system 40 directs one ormore cover actuators 65 to open or close cover panel(s) 62, for exampleby actuation of mechanical spring-bias elements 65, or utilizingelectro-active or voltage-activated materials or memory metal actuatorcomponents 65. Additional electro-active polymers and other materialsmay also be utilized, for example by extending electro-active cornerelements 64 outward from cover panel(s) 62 to redirect impact energyaway from device 10 and cover glass 12 into energy-absorbing components64, or other damping and shock absorbing materials within cover panels62.

Adjacent cover panels 62 can also be rolled into a partially or fullycoiled shock and impact-absorbing configuration, as shown in FIG. 6(arrow C). For example, cover panel(s) 62 may be positioned in a closed,partially open, or coiled (curled) configuration, either adjacent coverglass 12 or the side or back surface of device 10. In addition, device10 may be oriented so that cover system 60 lands first, and the impactenergy is absorbed by shock absorbing (e.g., soft) materials of coverpanels 62, or dedicated impact-absorbing elements 64.

Depending upon impact geometry, for example, cover system 60 can also bepositioned in a spring-like energy absorbing or shock-absorberconfiguration, in order to increase the impulse time of the impact, andreduce the resulting forces and loads on device 10. Alternatively, oneor more cover panels 62 can be flapped (actuated) open or closed (arrowO/C), either in a single motion or by repeated actuation, in order toslow the fall of device 10. Cover panels 62 may also be actuated orflapped to alter the rotational attitude A, in order to produce a morefavorable impact orientation for device 10, and/or a more favorableenergy absorbing configuration for cover panels 62.

FIG. 7 is an alternate perspective view of electronic device 10. In thisexample, cover system 60 is configured as a case or enclosure system fora tablet-type computing device 10, with front cover panels 62 and backand side cover sections 63. Countermeasure system 40 includes actuatedcomponents 65, and cooperates with sensor and processor components indevice 10 and/or cover 60 to open or close cover panels 62 based on adrop event or other potential hazard, as described above.

Alternatively, one or more cover panels 62 may be actuated or deployedin order to change the orientation of device 10 prior to impact, forexample in order to orient device 10 to absorb impact energy in coverpanels 62. Alternatively, internal or external mechanisms may beactuated to orient device 10 so that impact energy is absorbed by rearor side panels 63 of cover system 60, for example when cover panels 62are absent.

In some designs, cover system 60 may also include actuated members 66 inone or more back or side panels 63, for example an expanding orcontracting ring mechanism assembly 66 disposed about the periphery ofcover 60, as shown in FIG. 7. On or more ring-type actuator elements 66may be configured to deploy prior to impact, so that impact energy isredirected away from device 10 and cover glass 12, into energy-absorbingcomponents 64 in ring actuator 66. Suitable deployment mechanisms foractuator elements 66 include spring bias, electromagnetic, and pneumaticactuators.

Additional actuated energy absorption elements 64 may also be provided,for example electro-activated elements 64, as described above,pneumatically actuated elements 64, and/or fluid-filled offluid-actuated elements 64. In general, energy absorption elements 64can be positioned or actuated to project in a proud relationship withrespect to device 10, and the adjacent components of cover system 60(arrows P), in order to absorb impact energy. In some applications, amagnetorheological (MR) fluid may also be utilized, whereby the dampingand energy-absorption characteristics of individual members 64 can beselected based on the velocity and orientation (or attitude) of device10, and other impact geometry data, for example using a magnetic signalto alter the viscosity of the MR fluid.

One or more energy absorbing elements 64 may also be formed of a durableenergy-absorbing material such as fiberglass, a rubber or silicon basedmaterial, or a composite material with suitable damping and shockabsorbing properties. In these embodiments, energy-absorbing members 64may be distributed in various locations within cover panels 62 and sideand rear panels 63, for example in different corner and edge locationsof cover system 60, as shown in FIG. 7. In additional embodiments, oneor more panel sections 62 and/or 63 of cover system 60 may be formed inwhole or in part of fiberglass, rubber, silicon, impact foam, or othersuitable energy-absorbing composite material, or such materials may beused to line the edges or corners of panels 62 and 63, proud of device10, in order to redirect impact energy away from device 10 into coversystem 60.

Auxiliary electromagnets 67 can be utilized to hold cover panels 62 inplace, in the event that device 10 is dropped. In these examples,mitigation system 40 may be configured to actuate auxiliaryelectromagnets 67 when a drop event or other hazard is indicated,providing additional magnetic force to hold cover system 60 closed overcover glass 12, redirecting impact energy away from device 10 and intoenergy-absorbing components 64.

FIG. 8 is a perspective view of device 10, with cover system 60 in anejected position. In this configuration, device 10 is operable to ejectone or more cover panels 62 (or 63) of cover 60, for example byreversing the polarity of cover coupling electromagnets 68A or 68B, orby repositioning or rotating (flipping) internal magnets 68A and/ormagnets 68B. Based on the orientation A of device 10 and the proximityof any potential contact surface S, cover system 60 can also be ejectedso as to reach surface S before device 10, redirecting impact energyaway from cover glass 12 and other sensitive components by cushioningthe (later) impact of device 10 with cover system 60.

In particular applications, magnets 68A and 68B may be arranged withalternating (and complementary) polarity, so that a relatively small(e.g., linear) repositioning of internal device magnets 68A (arrow R)with respect to external (cover) magnets 68B results in a substantialrepulsive force, ejecting cover system 60 (arrow E). Alternatively,electromagnetic devices 68A or 68B may be used, in order to change therelative field polarity based on a current signal.

Additional drop damage mitigation techniques are also contemplated. Forexample, audio devices such as speakers 22 can be driven or actuated togenerate one or more air pulses prior to impact. In this configuration,audio devices 22 may act as an air brake to reduce impact velocity, forexample when utilized just prior to a face-drop type impact.Alternatively, one or more audio devices 22 may be actuated to generateaudio pulses for increasing the impulse time, and thus to reduce theimpact forces and stress loading on device 10.

An ejected cover system 60 may further be configured to reduce impactvelocity via magnetic interactions with device 10. In theseapplications, any number of cover magnets 68A and/or diamagneticmaterials may be distributed in cover panels 62 to generate an opposingfield with respect that of internal magnets 68A of device 10, asdistributed about the perimeter or along the front and back surfaces ofhousing 16 and/or cover glass 12. Cover panels 62 may also includemagnetic, ferrous, or ferromagnetic materials, allowing device 10 todetermine the relative position, velocity, and field orientation ofcover system 60 via a magnetic field sensor 42, as described above.

Device 10 may also actuate internal magnets (e.g., electromagnet orrotating permanent magnets) 68A to generate an opposing field, withrespect to that of ejected cover system 60, in to order to reduce impactvelocity. Alternatively, cover panels 62 may utilize diamagneticmaterials, in order to generate an inherently opposing fieldconfiguration, with respect to that of device 10. Device 10 may alsoactuate various internal magnets 68A to generate fields of eitherpolarity, in order generate torque on device 10 by magnetic interactionwith ejected cover system 60. In particular, this allows device 10 toproduce a more favorable impact attitude A, via magnetic interactionwith the corresponding fields of the magnetic components in cover panels62.

While this invention has been described with reference to exemplaryembodiments, it will be understood by those skilled in the art thatvarious changes can be made and equivalents may be substituted forelements thereof, without departing from the spirit and scope of theinvention. In addition, modifications may be made to adapt the teachingsof the invention to particular situations and materials, withoutdeparting from the essential scope thereof. Thus, the invention is notlimited to the particular examples that are disclosed herein, butencompasses all embodiments falling within the scope of the appendedclaims.

We claim:
 1. A system comprising: an electronic device comprising: ahousing; a display coupled to the housing; a motion sensor within thehousing and configured to sense motion of the electronic device; and aprocessor within the housing and configured to determine a drop eventbased on information from the motion sensor; a cover coupled to theelectronic device and comprising a panel having an open position and aclosed position, wherein, in the closed position, the panel overlies thedisplay; and an actuator configured to detach the panel from theelectronic device in response to the processor determining the dropevent.
 2. The system of claim 1, wherein the actuator is configured tocompletely detach the cover from the electronic device.
 3. The system ofclaim 1, wherein: the panel is a first panel; the cover comprises asecond panel; and the actuator is configured to fold the first panelrelative to the second panel in response to the processor determiningthe drop event.
 4. The system of claim 1, wherein the panel isconfigured to change an orientation of the electronic device when thepanel is detached from the electronic device.
 5. The system of claim 1,wherein the actuator is an electromagnetic actuator operable to open orclose the panel in response to an electric current.
 6. The system ofclaim 1, wherein the actuator is a magnetic actuator configured todetach the panel from the electronic device by magnetically repellingthe panel from the electronic device.
 7. The system of claim 1, whereinthe actuator is further configured to flap the panel during the dropevent.
 8. A method of protecting an electronic device, comprising:sensing motion of an electronic device indicative of a drop event; andin response to sensing the motion indicative of the drop event,detaching at least a portion of a cover from the electronic device;wherein: the cover comprises a panel having an open position and aclosed position; and in the closed position, the panel overlies at leasta portion of a display of the electronic device.
 9. The method of claim8, wherein the operation of detaching at least the portion of the covercomprises completely detaching the cover from the electronic device. 10.The method of claim 9, wherein the operation of completely detaching thecover comprises detaching the cover such that the cover lands on animpact surface and the electronic device lands on the cover.
 11. Themethod of claim 8, wherein the operation of detaching at least theportion of the cover comprises moving a magnet in the electronic deviceto detach at least the portion of the cover via magnetic repulsion. 12.The method of claim 11, wherein the operation of detaching at least theportion of the cover alters an orientation of the electronic device viamagnetic interaction with the cover.
 13. The method of claim 8, whereinthe operation of detaching at least the portion of the cover reduces aspeed of the electronic device during the drop event.
 14. The method ofclaim 8, wherein: the operation of detaching at least the portion of thecover comprises detaching the panel from the display; and the methodfurther comprises flapping the panel to alter an orientation of theelectronic device during the drop event.
 15. The method of claim 8,further comprising, after detaching at least the portion of the coverfrom the electronic device, articulating the cover into ashock-absorbing configuration.
 16. A system comprising: an electronicdevice, comprising: a housing; a cover glass coupled to the housing; anda processor within the housing and configured to determine a drop event;a cover comprising a panel having an open position and a closedposition, wherein, in the closed position, the panel overlies the coverglass; and an actuator configured to move the panel into the closedposition in response to the processor determining the drop event. 17.The system of claim 16, wherein: the cover further comprises adeployable energy-absorbing element; and the processor is configured tocause the energy-absorbing element to deploy in response to theprocessor determining the drop event.
 18. The system of claim 17,wherein the deployable energy-absorbing element comprises amagnetorheological fluid.
 19. The system of claim 16, wherein: theactuator is a first actuator; the electronic device further comprises: abutton coupled to the housing and having an actuation face substantiallyparallel with the cover glass; and a second actuator configured toextend the button proud of the cover glass; and the processor isconfigured to cause the button to extend proud of the cover glass inresponse to the processor determining the drop event.
 20. The system ofclaim 16, wherein: the panel is a first panel; the cover furthercomprises a second panel; and the actuator is positioned between thefirst and second panels.